1. Field of the Invention
The present invention relates to software design of software architectures and, in particular, to the design of a software component architecture for the development of extensible tier software component applications, including compiled, interpreted, and on-the-fly applications.
2. Description of the Related Art
A variety of techniques are used by a programmer or code developer to design or generate software program code. In one approach, software applications are designed as “monolithic” structures in which the various functions, such as data storage and application logic, are completely entwined. For example, given a set of system specifications and functions which are to be implemented by a given application or program, the code developer designs a monolithic, independently executable program which implements the desired functions. The programmer may use, for example, a high-level programming language such as C++ and a code development tool to generate the high-level language, which is then compiled by a compiler to provide an executable version of the program.
One problem with this approach is that the applications are difficult to maintain, and separate functional portions of the program are difficult to reuse because all portions of the program are entwined and application-specific.
Accordingly, in the software field various software architectures have been developed in which application functionality is broken down into smaller units, such as objects or components. These units may be assembled to provide the overall functionality for a desired application. For example, a group of components may be assembled and compiled to provide a stand-alone, executable program. Alternatively, the components may be invoked and used in real-time, when the component's functionality is needed.
Because of the resource expenditure necessary to develop these units, it is desirable to be able to reuse these units, so that their functionality may be employed in subsequent applications without having to “re-invent the wheel” each time this functionality is needed. In current software architectures, such as two-tier and three-tier architectures, some portions, such as data repositories and user interfaces, are relatively easy to reuse. However, other types of components, such as those implementing application logic, are still clumped in large blocks, making reuse of these components or their various functions difficult. There is a need, therefore, for improved software component architectures and related software component development techniques that avoid the drawbacks of the prior art.